A b
s
t
r a c
t
P
at
ric
i
a
D
ra m
m
ey
:E
va
lu a
t
in
g
M
i
c r ob ia
l P
a rt
i
t
i
o nin
g
A l
o ng
t
h
eS
t
o
rm w
at
e rT
r a n sp
o rt
C h
ai
n an
d i
t
sh
n
p
a ct
on
t
h
eE
ff
e ct
iv e n e s s o
f
W
et D
et
en
t
i
on
P
o nd
s(
U
nd
e rt
h
ed ir e c
ti
o n of G
r eg
o ry
C h
a r a ck l i
s)
W
et
d
et
e nti
on
b
a sin s a r e
am
o ng t
h
em
o
st
c om
m
on
st
r u ct
u r al b
e st
m
an
ag
em
e nt
p
r a ct
i
c e s(
B
M
P
s)
b
ei
ng
i m
p
le
m
e nt
ed
a s am
e a n s of
c om
p
l
y
i
ng
w i
t h
f
ed
e r al
P
h
a s eI I
s
t
o rm w
ate r r u
l
e s a nd
i m p
e nd
i
ng T
ot
al
M
a xi
m
um
D
ai
l y L
o ad
(
T
M
D L
)
l
im
i
t
s.T h
ee
f f
e ct
iv e n e s s o
f
t
h
e s eb
a si
n sf
o r r em
o v al
o
f m ic r o
b i
al
c o nt
am
i
n a nt
s, o
n
e of
t
h
em
o st
f
r eq
u e nt
c a u s e s of w
at
e rq
u al i
t
y i m
p
ai
rm
e nt
,m
ay b
e si g
ni f
i c ant
l
y
af f
e ct
ed b
y t
h
ed
eg
r e eo
f m i
c r ob i
al
a s s o ci
at
i
on
w i
t
h
p
a rt
i
cl
e si
n
st
o rm w
at
e r.L
i
t t
l
ei
sk
n
ow
nw i
t h
r eg
a rd
t
ow h
e r em
i
c r ob i
al
-p
a rt
ic
l
e a s s o ci
at
i
o n s a r ei
nit
i
at
ed w i
t
h i
nt
h
e st
o rm w
at
e rt
r a n sp
o rt
ch
ain
a s
f lo
w
t
r a v el
sfr
om
up
l
an
d
s o u r c e s(
e.g
.,
l
aw
n s,p
a rk
i
ng
l
ot
s)
t
h
r o ug
h
st
o rm
s ew
e rs
y
st
em
s a nd
B
M
P
s a nd fi
n al l
y
o nt
o r e c ei
vi
ng w
at
e r s.A
si m i l
a rl
a ck
of in
f
o rm
at
i
o
ne x
i
st
s o nth
e r el
at
i
v e c o n c e nt
r at
i
o n s of
m
i
c r ob
e s at
e a ch
p
oin
t
in t
h
et
r an
sp
o rt
ch
ai
n .B
ot
h
of
th
e s ef
a ct
o r sh
a v ei m
p
o rt
a nt
i m
p
l i
c at
i
on
sfo r
t
h
el
o c at
i
o n of w
et
d
et
en t
i
o nb
a si
n
sw
it
h in
aw
at
e r sh
ed
.T
h i
s st
ud
y t
r a ck
ed
t
h
e c o n c e ntr a
t
io n s a
n
d
p
a rt
it
i
o nin
g
b
eh
a vi
o r of
t
h
r e ein
d i
c at
o r o rg
a ni
sm
s(
f
e c al
c ol i f
o rm
,E
c ol
i
, e nt
e r o c o c ci
)
t
h
r o ugh
o ut t h
et
r a n sp
o rt
c
h
ai
n a nd
al
s o e xp
lo r e
d
t
h
ei
m
p
a ct
s of
p
a rt
i
t
io n
i
ng
o nw
et
p
o nd
r em
o v al
ef fi
ci
e n cy
.R
e s ul
t
s s ug
g
e st
th
at t
h
ed
eg
r e e of m i
c r ob i
al
p
a rt
i
t
i
o ni
ng d
o e s n ot
v a ry g
r e at
l y
t
h
r o ugh
o ut
t
h
etr a n s
p
o rt
ch
ain
(
i
e.m i
c r ob i
al
-p
a rt
ic
l
e a s s o cia
t
io n
is
i
ni
ti
at
ed
at t
h
e s o u r c e)
.M
i
c r ob i
al
c o n c e nt
r at
i
o n sw
e r eh i
g
h
e r at
th
e r e si d
e nt
i
al
up
l
a nd
si
t
e s(
r u n of f
,w
et p
o nd
i
nfl
ow
a nd
o ut
fl
ow
)
t
h
a nin
t
h
e st
r e am
.T h
e o v e r al l
r edu c
t
i
o ni
nm
i
c r ob i
al
c o n c e nt
r at
i
o nb
r o ug h
t
ab
o ut
b y
t
h
ep
on
d
sw
a sl
e sst
h
an t
h
at
as sum
ed b y
m
o st
r eg
ul
ato
ry
ag
enci
es,b
ut
t
h
ep
o nd
s
d i d
sh
ow
so
m
e e vi d
e n c e of p
r ef
e r e nt
i
al l
y
r em
o vi
ng p
a rt
i
cl
e-a s s o c
i
at
ed f
e c al
c o
l
i f
o rm
a nd
E
. c ol i
.T
h
e s efi
n
d
i
n
g
s sh
ou
l d
p
r o vi
d
ein
si
g
h
t
su
s ef
ul i
n t
h
ed
e si
g
n
an
d
i m
p l
em
e nt
at
io n
of
st
o rm
w
at
e rm
a n ag
em
e nt
str a
t
eg
i
e s.A
c
k
n o
w l
e
d g
e
m
e n
t
s
T h
i
sw
o rk
w
a s s up p
o rt
ed b
y
N C
D
E N R N
P
S
3 1
9
(
c on t
r a ct E
W
0 7 0 1 0
)
a nd
t h
eN
o rt
h C
a r oh
n aU
rb
a nW
at
e rC
o n s o rti
um
-St
o rm w
at
e rG
r o up
/N C
W
at
e rR
e s o u r c e sR
e s e a r ch I
n st
i
t
ut
e(p
r oj
e ct n
o .5
0 3
6 8
)
.
S
p
e ci
al
t
h
a nk
sg
ot
oL
ei
g h
-
A
n n
eK
r om
et
i
s , aP
hD
c a n
d
i d
at
ew
o rk
i
ng
o nm i
c r ob i
al
p
a rt
i
t i
o ni
ng
i
nN
o rth
e a st
C
r e ek
, a nd
M
ay
r el i
sN
a r v a e za n
d S
t
e v eR
u s s o,w h
o a s si
st
ed w i
th l
ab w
o rk
.T
a
b l
e o
f C
o n
t
e n
t
s
L
is
t
of
F
i g
u r e s vi
L
i
st
of
T
ab l
e s vii
In
t
r od
u ct
io n
.M
eth
od
sS
am
p l
i
ng
4
L
ab
o r at
o ry
A
n al
y
si
s6
St
at
i
st
ic a
l
A
n
al
y
si
s8
R
e s ult
s a nd D i
s c u s sio n
P h
a s eL
Si
n
g l
eG
r ab S
am
p
l
eSa
m
p
l i
ng
9
P
h
a s eI
L
I
nt
r a st
o rm Sa
m p
l
i
n
g
14
C
o n cl
u si
o n s18
A
p
p
e nd i
c e sA
:St
at
i
st
i
c al
A
n
al
y
si
sS
um
m
a ry
33
B
:Sin
g
le
G
r ab Sa
m
p
le
a nd
M
e a nC
o n c en
t
r at
i
on
R
em
o v al
s37
C
:R
e si d
en
c eT i
m
e s a nd
I
d
e al
R
e a cto r
C
om
p
a ri
s o n s38
D
:I
n tr a s
t
o rm E
v e nt
M
ea
nC
o n c en
t
r ati
on
C
al
c ula
t
io
n
s4 7
E
:I
nt
r a st
o rm R
ai
nf
al l
a nd St
o r ag
eC
al
c ul
ati
o n s4 9
F
:I
n
tr a s
t
o rm P
a rt
i
cl
eE
v e nt
M
e a nC
o n c e nt
r at
i
on
s5 4
G
:St
o rm
a nd B
a ck
g
r o u nd C
o n c en t
r ati
o n s a nd C
o nf i d
e n c eI
nt
e r v al
s5 7
L i
s
t
o
f F i
g
u r e s
F
i
g
u r e1
:S
t
o rm w
at
e rt
r an
sp
o rt
ch
ai
n2 2
F
i
g
u r e2
:N
o rt h
e a st
C
r e ek w
at
e r sh
ed
2 3
F i g
u r e3
:P
a rt
i
ti
on
i
n
g
t
e ch
n
i q
u e s ch
em
at
ic
2 4
F
i
g
u r e4
:A
v e r ag
e st
o rm b
a ct
e ri
al
a nd
p
a rt
i
cl
e c o n c e nt
r at
i
o n s2 5
F
i
g
u r e5
:S
t
o rm
s et t
l
e ab l
efr
a ct
i
o n s of b
a ct
e ri
a
a nd p
a rt
ic
l
e s2 6
F
i g
u r e6
:T
ot
al in
fl
ow
v s. o ut
fl
ow
2 7
F
i
g
u r e7
:Se
t t
l
e ab l
ein
fl
ow
v s. o ut
fl
ow
2 7
F
i
g
u r e8
:I
n t
r a st
o rm b
a ct
e ria
l
a nd
p
a rt
ic
l
e c o n c e nt
r at
i
o n s3 0
F
i g
u r e9
:E
M
C
v ol
um
e c al
c ul
at
i
o nt
e ch
n
i
q
u e3 1
F i g
u r e1 0
:P
a rt
i
cl
ed
i
st
ri b
ut
i
o nE
M
C
3 3
L i
s
t
o
f
T
a
b l
e s
T
ab l
e1
:S
t
at
is
ti
c al
a n al
y
si
s2
8
T
ab l
e2
:G
e om
et
ri
cm
e a n c o n c e nt
r at
io n
r em
o v al
2
9
T
ab l
e3
:A ri
t
h
m
et
i
cm
e an
c on
c e nt
r at
i
o n r em
o v al
2
9
T
ab l
e4
:I
nt
r a st
o rm
E
M
C
an
d
E R
r e s ul
t
s3 2
I
nt
r od
u
ct i
o nT h
eE P
A
e st
i
m
at
e st
h
at 4 0
%
of
a s s e s s ed w
at
e r si
nt
h
eU
n
i
t
ed S
t
at
e sd
o n ot
m
e et
w
at
e rq
u aU
t y
st
an
d
a rd
s,
w i
t
h
m
i
c r ob i
a
l
c o nt
am
i
n at
i
o ni d
en
t
i f i
ed
a s al
e ad i
ng
c a u s e of
i m
p
ai
rm
e nt
(
U S
E P
A 2
0 0 7
b
)
.F
e c al
c o nt
am
i
n
at
i
o n of
n at
u r al w
at
e r si
s a n e n vir o n
m
e nt
al
a n
d h
um
a nh
e al
t
h
c o n c e r nw
o rl d w i d
e, a s r e c r e at
i
o n al
u s e s,d
ri
nk i
ng
w
at
e rq
u al
i
t
y
,a
q
u a c ul
t
u r e a ct
iv
i
t
i
e s a nd
a e st
h
et
i
c s c a n al l b
e n eg
at
iv e
l
y
i
m
p
a ct
ed
(
N R C
2 0 0 4
)
.R
e c r e at
io
n
al
e xp
o s u r et
ow
at
e r c o nt
am
i
n
at
ed w i
t
h
m
i
c r o o rg
an
i
sm
sm
ay
le a
d
t
og
a st
r oin
t
e st
in a
l
a nd
r e sp i
r at
o ry i l l
n e s s(
H
ai l
e et
al
.1 9
9 9
; P
o nd 2 0 0 5
;
W
ad
e et
al
.2 0
0 3
)
,a n
d
st
at
is
t
i
c al l i
nk
sh
a v eb
e e n ob
s e r v ed b
et w
e e n r ain
fa
l l
an
d d i
s e a s e o ut
b
r e ak
si
n s om
eU S w
at
e r sh
ed
s(
Cu r r
i
e r o et
al
.2 0 0 1
)
.T h
e1
9
7 2
C
l
e a nW
at
e rA
ct
(
C
W
A
)
e st
ab
l
i
sh
ed
t
h
eN
at i
o n al P
ol l
ut
a nt
D
i
s ch
a rg
eE
l
i
m i
n at i
o nS
y
st
em
(
N P
D
E
S
)
,w h i
ch
si
g
ni
f
i
c a nt l y
r ed
u c ed
c o nt
am
i
n at
i
o nf
r om
p
oin
t
s o u r c e s s u c
h
a sw
a st
ew
at
e rt
r e at
m
e nt p
la
n
t
s a nd i
ndu s
t
ri
al f
a ci l i
t
ie s
H
ow
e v e r,t
h
eC
W
A
's
g
o al
of
m
ak i
ng
al l w
at
e r s "f i
sh
ab l
e an
d
sw i m
m
ab l
e "h
a s n ot
b
e e n a ch ie v e
d i
nm
a ny
a r e a sd
u et
ot
h
e c o nt
ri b
ut
i
o n s of
n o np
oin
t
s o u r c e s,
p
ri
m
a ri l
y
st
o rm w
at
e r r u n of f
(
N R C
2
0
0
1
)
.S
t
o rm
r u n of f l
e ad
st
o el
e v at
ed
c o n c e nt
r at
io n s o
f
m
i
c r ob
e si
n r e c ei
vi
ng
w
at
e r s,
w i
t
h h
um
a n s,h
v e st
o ck
,w i l d
a nd d
om
e st
i
c a ni m
al
s al l
s e r vi
n
g
a sp
ot
e nt
i
al
s o u r c e s o
f f
e c al i
nd i
c at
o r s a nd
p
at
h
og
e n s(
A
t
h
e rh
ol
t
et
al
.1
9 9
8 ;
K i
st
em
an n
et
al
.2 0
0
2 ;
M
ed
em
a et
al
.2 0 0 3
;
N
ob l
e et
a
l
.2 0 0
3
)
.I
ni
t
i
at
e
d i
n1
99
0
a nd
e xp
a nd
ed i
n1
9 9
9
,N
P D
E S
s
t
o rm
w
at
e r r eg
ul
at
i
o n s st
i p
ul
at
et
h
at
n ew m
im i
ci
p
al d
e v elo
p
m
e nt
sm
u st
i m
p l
em
e nt
s
t
o rm
w
at
e rm
a n ag
em
e nt
st
r at
eg
i
e si
n clu
d i
ng
a c om b i
n at
i
o n of
st
r u ct
u r al
a nd/
o r n o n¬s
t
r u ct
u r al B
e st
M
a n ag
em
e nt P
r a ct
i
c e s(
B
M
P
s) (
U S
E P
A
1
9 9 9
)
.S
t
o rm
w
at
e ri
np
ut
s a r ea
l
s o ap
ri
m
a ry
c on
si d
e r at
i
o nw h
e n s et t
i
ng
p
ol l
ut
a nt
-sM
a xi m
um
D
ai
l y L
o ad
s(
T
M
D
L
s)
t
h
at
a r ed
e v el
op
ed f
o ri
m
p
ai
r ed
w
at
e rb
od i
e si d
e nt
i f i
ed
b y
st
at
e s.T
h
e s ew
at
e rb
od i
e s a r e r eg
ul
at
ed
u nd
e r s e ct
i
o n3
0
3
(
d
)
of t
h
eC
W
A
, an
d
t
h
eT
M
D L p
r o c e s si
n v ol
v e si d
e nti f
y
i
ng
a nd
q
u a nt
i f
y
i
n
g
c o nt
ri
b
ut
i
o n sfr
om
p
oi
nt
a nd
n o n
p
oi
nt
s o u r c e s,t
h
e nd
et
e rm i
ni
ng t h
e r ed
u cti
o n r eq
ui
r ed
fr
om
e a ch
s o u r c ei
n o rd
e rt
om
e et
w
at
e rq
u al i
t y
st
a nd
a rd
s(
N R C 2 0 0 1
)
.S
ed i m
e nt
at
i
o n-
b
a s ed
B
M
P
s, s u c
h
a ss
t
o rm w
at
e rw
et p
o nd
s, a r e c om
m
o nl y i
m
p l
em
e nt
ed i
n o rd
e rt
o a ch i
e v e c om p l i
a n c e, a nd
t
h
e ef fi
ci
en
cy
w i
t
h
w
h
i
ch
t
h
e s ep
o nd
s r em
o v em
i
c r ob i
al
c o nt
am
i
n
an
t
si
s an
i
s su
e of
s
i
g
ni fi
c an
t
c o n c e r n(
U SE P
A
2
0
0 1
)
.T
h
em
e ch
a ni
sm
s of m i
c r ob i
al
r em
o v al i
n st
o rm w
at
e rw
et
p
o nd
s, a sw
el l
a st
h
ei
re
f f
i ci
e n cy
, a r e n ot
w
el l
q
u a nti f
i ed
o r u nd
e r st
o od
(M
uth
uk
ri
sh
n
a n et
al
.2
0
0
4
;
U SE
P
A
2 0
0
7
a;
U S
E PA
an
d A SC E
1
9
9
9
)
.A
n
i
m
p
o rt
a nt
c o n si d
e r at
i
o nw h
e ni
n v e sti
g
ati
ng
s e
d i m
e nt
at
i
o n a s a r em
o v al
m
e ch
a ni
sm
w i l l b
em i
c r ob i
al p
a rti
t
i
o ni
ng
b
eh
a vi
o r.V
i
r u s e s,b
a ct
e ri
a, a nd
p
r ot
o z o a np
a r a si
t
e s c a nb
e a s s o ci
at
ed w it
h
p
a rt
i
cl
e si
nth
ew
at
e r c ol
um
n,a n
d
t h
o s et
h
at
a r ew i l
l g
e n e r al l
y
h
a v e af
a st
e r s ed i m
e nt
at
i
o n r at
eth
a nth
ei
rfr
e ep
h
a s e(
i
.e.u n a
t t
a ch
ed
)
c o u nt
e rp
a rt
s.S
e v e r al
st
ud i
e sh
a v eb
e e n u nd
e rt
ak
e nt
oi
n v e sti
g
at
et
h
efr
a ct
i
o no
f
v a ri
o u so
rg
a ni
sm
s a s s o ci
at
ed w i
t
h p
a rti
cl
e s.M
o st
of
t
h
e s eh
a v e em
p l
oy
ed
f
il
t
r at
i
o n-b
a s ed
s ep
a r at
i
o nt
e ch
ni q
u e s(
A
u e r a nd N i
eh
a u s1 9 9
3
;
J
e ng
et
al.
2 0 0
5 ;
M
ah l
e re
t
al
.2
0 0
0 ;
S
ch i l l i
ng
e r a nd G
a nn
o n19 8 5
)
, a nd
th
e s e st
ud i
e sh
a v e s ug g
e st
ed
t
h
at
s om
efr
a ct
i
o n of f
e c al i
nd i
c at
o rb
a ct
e ri
ai
s a s s o ci
at
ed w i
t
h p
a rt
i
cl
e s.H
ow
e v e r,t
h
efi l
t
r at
i
o na
p p
r o a ch
t
o s ep
a r at
i
o ni
sb
a s ed
o nl
y
o np
a rti
cl
e si
z e, n ot
d
e n si
t y
,b
ot
h
of w h i
ch
af f
e ct
s e
t
tl i
ng
v el
o ci
t y
.G i
v en
t
h
at
th
e s ep
a rt
i
cl
e s c a nb
e c om
p
o s ed
of d
e n s ei
n o r
g
a ni
cm
at
e ri
al
(
eg
. si l i
c at
e s, cl
ay
s)
,l
e s sd
e n s e o rg
a ni
cm
at t
e r, o rb
oth
, a n ap p
r o a ch t h
at
d
i
s c ri
m
i
n at
e sb
et w
e e np
a rt
i
cl
e s a nd p
a rt
i
cl
em
ay b
e v al
u ab l
ei
n a s s e s si
n
g
t
h
e s et t
l i
ng
a nd
t
r a n sp
o rt
ch
a r a ct
e ri
st
i
c s of
at t
a ch
ed
m i
c r ob
es
.S
e v e r al
re
c e nt
st
ud i
e sh
a v e em p l
oy
ed
a c al i b
r at
ed
c e nt
ri f
ug
at
i
o nm
et
h
od
,w
h i
ch
s ep
a r at
e s s u sp
e nd
ed
m
at t
e rb
a s ed
o n s et
t
l i
ng
v el
o ci
t
y
,t
oe
v al
u at
em i
c r ob i
al
p
a rt i
t
i
o nin
g
(
C
h
a r a ck l
i
s et
al
.2 0 0 5
;
F
ri
e s et
al
.2
0
0 6
;
R
r om
et
i
s et
al
.2 0
0 7
)
.h
it
h
e s es
t
udi
e s,b
a ct
e ri
al
,p
r ot
o z o a n a nd
vi
r al i
nd i
c at
o r sw
e r e e v al
u at
ed
,w i
t
h
r o ug
h l
y 7
0
%
of C
.p
e rf
ri
ng
e n s sp
o r e s,
4 0
%
of b
a ct
e ri
al i
nd i
c at
o r s(
f
e c al
c ol i f
o rm
s,E
. c ol
i
, a n
d
e nt
e r o c o c ci
)
a n
d
1 0
%
of
t
ot
al
c ol i
p
h
ag
ef
o u nd
t
o a s s o ci
at
ew i
t
h
p
a rt
i
cl
e s.A l
t
h
o ug
h
a si
g
ni f
i c a nt
l
e v el
o
f m i
c r ob i
al
-p
a rt
i
cl
e a s s o ci
at
i
o nw
a s ob
s e r v ed i
nt
h
e s e st
ud i
e s, r e s ul
t
s s ug g
e st
ed
t h
at
m
a ny
of
t
h
e s ep
a rt
i
cl
e sw
e r e r el
at
i
v el
y
sm
al l
, a nd
t
h
e a ct
u al
ef f
e ct
i
v e n e s s of
s e
d i m
e nt
at
i
o n-b
a s e
d
B
M
P
sf
o rm
i
c r ob i
al
r em
o v al
r em
ai
n s u nd
et
e rm i
n ed
.S
t
ud i
e sh
a v e sh
ow
n r em
o v al
of
i
nd i
c at
o r o rg
a ni
sm
si
sh i
g
h l
y
v a ri
ab l
e o v e rb
ot
h
d i f f
e r e nt
B
M
P t y p
e s a nd
st
o rm
e v e nt
s(
B
o rd
e n et
al
.1
9 9 8
;
D
a vi
e s a nd B
a v o r2
0 0 0
;
D
a vi
e s et
al
.2 0 03
;
M
al l i
n et
al
.2
0 02
)
.A l
t
h
o ugh
"t y
p i
c al
" r em
o
v al
of b
a ct
e ri
ai
ns
t
o rm w
at
e rw
et p
o nd
sh
a sb
e e n e st
i m
at
ed
at
6
5
%
(
U S
E P
A
2 0 0 7
a)
, st
ud
i
e s u si
ng
v a ri
o u ss a
m
p
l i
ng
a nd
c al
c ul
at
i
o nm
et h
od
sh
a v e e st
i m
at
ed b
a ct
e ri
al
r em
o v al
fr
om
b
et
w
e e n -1 5
%
a n
d 9 9 %
(
C A L
T R
A N S
2 0
0
4 ;
M
al l i
n et
al
.2
0 0 2
;
U S E
P
A 2
0 0 7
b
)
.A l
t
h
o ug h
s e
d i m
e nt
at
i
o ni
s c om
m
o nl
y
a s s um
ed
t
ob
e ap
ri m
a ry
m
e ch
a ni
sm
of
m
i
c r ob i
al
r em
o v al i
nw
et
p
o nd
s,t
h
e r el
at
i
v e r em
o v al
at
t
ri b
ut
ab l
et
o s edi
m
e nt
at
i
o n v e r s u s ot
h
e rm
e ch
a ni
sm
s(
e.g
., s ol
a ri
n a ct
i
v at
i
o n,p
r ed
ati
o n)
h
a s n ot
b
e e nq
u a nt
i fi
ed
(
S
t
r u ck
et
al
.2
0
0
6
)
.W
h
en a n
d w h
e r em
i
c r ob i
al
-p
a rt
i
cl
e
a s so
ci
at
i
on
o c cu
r s al
on
g
t
h
et
r a n sp
o rt
ch
ai
nfr
om
s o u r c e(
e.g
.l
aw
n s,p
a rk i
ng l
ot
s)
th
r o ug h
th
e st
o rm
s ew
e rs
y
st
em
, an
d
e v e nt
u al l y
t
ot
h
e r e c ei
vi
ng
w
at
e r(F i g
u r e1
)
i
s a n ot
h
e r a r e at
h
at
h
a s n ot
b
e e nf
i
il l
y
e xp
l
o r ed
a nd
m
ay
b
ea n
i m p
o rt
a nt
f
a ct
o ri
ni d
e nt
i fy i
ng w h
e r eb
e st t
ol
o c at
e s ed i m
e nt
at
i
on
-b
s
i
g
ni fi
c a nt p
r op
o rt
i
o n s of m i
c r ob
e sin
st
r ee t
l
e v el
r u n of f
a r e at t
a ch
ed
t
op
a rt
i
cl
e s,s e
d i
m
e nt
ati
o n -b
a s ed B
M
P
sl
o c at
ed
n e a r up l
a nd
s o u r c e sm
ay
b
e ef f
e ct
iv e
i
n
r ed
u cin
g
l
o ad in
g
to
r e c ei
vin
g w
at
e rs
.C
o n v e r s el
y
,
i f
v e ry f
ew m i
c r ob
e s a r e at t
a ch
ed i
nt
h
e r u n of f
b
ut
r at
h
e rb
e c om
e at t
a ch
ed
aft
e r en t
e ri
ng
t
h
e r e c ei
vin
g
w
at
e r(
ei
t
h
e rt
h
r o ug
h i
nt
e r a cti
o nw
it
h
p
a rt
ic
l
e si
nt
h
ew
at
e r c olu
m
n o ri
n r e s u sp
e nd
ed
s ed i m
e nt
s)
, up
l
a nd
s ed i m
e nt
ati
o n-b
a s ed
B
M
P
sm
ay
b
el
e s s ef f
e ct
i
v e.T
od
at
el
i
t t
l
ew
o rk h
a sb
e e nd
o n et
oi d
e nt
i f
y
v a r
i
at
io n s
i
np
a rt
i
cl
e-m i
c r ob i
al
a s s o ci
at
i
o n at
d i
f
f
e r e nt p
oi
nt
si
nth
et
r an
sp
o rt
ch
ai
n .T
h i
s r e s e a r ch
e xp l
o r e sth
ep
ote n
t
ia
l
r ol
e of m i
c r ob i
al
p
a rt
i
ti
o ni
ng
i
nth
ee
f
f
e ct
iv e n e s s o
f
sto r
m
w
at
e rw
et p
o nd
sw h i l
e al
s o e v al
u at
i
ng
m
i
c r ob i
al
c o n c e nt
r at
i
o n s an
d
p
a rti
t
io n
i
ng b
eh
a vi
o r at
v a rio u s
p
oi
nt
s al
o ng t
h
et
r a n sp
o rt
ch
ai
n.T
h i
st y
p
e of in
f
o rm
at
io n
s
h
o ul
d
p
r o vi d
ei
n si
g
h
t
s u s efu
l t
oi d
e nt
i f
y
in
g t
h
et y p
e s a nd
l
o c ati
o n s of B
M
P
st
h
at
w
i l l b
ec a
p
ab l
e of i m
p
ro
vin
g
r e c ei
vin
g
w
ate r
q
u al i
t y
.M
et h
od
sSa
m p
l
i
ng
N
o rt
h
e a st
C
r e ek i
s a3 0 3
(
d
)
l i
st
ed
st
r e am w h
o s ei m
p
air e
d d
e si
g
n at
io n
i
s a r e s ul
t
of
el
e v at
ed f
e c al
c ol i f
o rm
c o n c e ntr a
t
io n s
.T h
ei m p
ai
r ed
s e ct
i
o n of
t
h
e c r e ek i
s8
.4
m i l
e sl
o ng
(
N C
D
E N R
2
0 0
3
)
a nd lo c a
t
ed w i
t
h in
D
u rh
am
,C h
at h
am
, an
d
W
ak
ec o u n
t
i
e si
nN
o rth C
a r ol i
n a(
F
i g
u r e2
)
.W
at
e rq
u aU
t y
c o n c e r n s a r e r el
at
ed
t
ob
ot
h
e c o
l
og i
c al
a nd
p
ub l i
ch
e al t
h i m p
a ct
,w i
t
h
t
h
el
at
t
e r st
em m in
g
fi
-o
m
t
h
ef
a ct t
h
at
N
o rth
e a st
C
r e ek dr a
i
n sin
t
oJo r
d
a nL
ak
e, a
lo c a
l dr
in
k i
ng w
at
e r s o u r c e a nd
r e c r e a
t
i
o n al
a r e a.T h
en o r
th
e r np
o rti
o n of
t
h
ew
at
e r sh
ed i
sl
o c at
ed i
nt h
e cit
y
of
D
u rh
am
a nd in c
l
ud
e s r e si d
e nt
i
al
a n
d
c om m
e r ci
al l
a nd
u s e s,w h i l
et
h
e s o ut
h
e r np
o rt
io n
is
l
a rg
el
y
r u r al
.L
a nd
u s ed
at
afr
om
w
et
l
and
w
i
t
h
t
h
e r em
ai
ni
ng 1 1
%
d
e si g
n
at
ed
a sp
a stu
r e , r ang
el
an
d
, c rop l
and
, orb
a r re n.S
t
r e am
sit
e1 i
sl
o c at
ed i
nt
h
e
ci
t y
of D
u rh
am
, a nd
st
r e am
si
t
e2
i
slo c a
t
ed i
n a r u r al
a r e aa
d
j
a c e nt
t
o aw
at
e rf
ow l i m
p
o un
d m
e nt
.A
w
a st
ew
at
e rt
r e at
m
e nt p l
a nt
d i
s ch
a rg
e sto
t
h
ec r e e
k b
et
w
e e nt
h
et
w
o st
e am
s am
p
l i
ng
si
t
e s.P
o nd
s1
a nd
2
a r e r eg
i
st
e r ed
st
o rm w
at
e rB
M
P
s(
w
et
d
et
e nt
i
o np
o nd
s)
l
o c at
ed i
n
a r e c e nt
l
y
d
e v elo
p
ed
r e si d
e nt
ia
l
a r e a of
D
u rh
am
.T
h
e ci
t y
of D
u rh
am w
a si
s s u ed
a nN
P
D
E
S
st
o rm w
ate r
p
e rm i
t
in
1
9 9
5
w
h
i
ch
r e
q
ui
r e sth
at
st
o rm
w
at
e rB
M
P
si
n n ew l
y
d
e v el
op
ed
a r e a sb
eb
ui l
t
i
n
a c c o rd
a n c ew i
t
h
N
o rt
h C
a r ol i
n aD
ep
a rt
m
en
t
of
E
n vir o n
m
e nt
a nd N
at
u r al
R
e s o u r c e s(
N C
D E
N R
)
o rD
u rh
am d
e si
g
ng
ui d
el
i
n
e s.T h
e s u rf
a c e a r e a,
d
ep t
h
,l
e ng t h t
ow i d
t h
r at
i
o s,d
am
c o n s
tr u c
t
io n
, s e ep
ag
e c o ntr o
l
, a nd
em
e rg
e n cy
sp
i
l l w
ay
r eq
ui
r em
e nt
sf
o rB
M
P
s a r es
p
e ci
f
i ed i
nt
h
e s eg
ui d
eU
n e s(
C i
t y
of D
u rh
am
P
ub l ic
W
o rk
s2 0 0
6
;
N C D
E
N
R
19 9 9
)
.W
et
d
et
e nt
i
o np
o nd
s a r ed
e si g
n
ed
t
oh
ol d
ap
e rm
a ne
nt
p
o ol
o
f w
at
e rw h i l
e als o
b
ein
g
c ap
ab l
eo
f
r et
ai
nin
g
th
e r u n off
r e s ult
i
ng
fr
om
1
in c
h
of
r ain
in
t
h
ed
r ai
n ag
e.T h
ed
r aw d
ow
n of
t
h
ete
m
p
o r a ry p
o ol
sh
o ul d
o c c u r4
8
t
o1
2
0 h
o u r sf
ol l
ow i
n
g
a st
o rm w i
t
h
1
i
n ch
of
r ai
n;
h
ow
e v e r,t
h
ed
r aw d
ow
np
e ri
od w
a s ob
s e r v ed
t
ob
e si
g
ni fi
c an
t
l
y
l
e s si
nb
ot
h
p
o nd
s(
u nd
e r16 h
o u r s)
.T
h
ed
e si
g
ng
ui d
el i
n e s al
s o a s s um
et
h
at
8
5
%
of
T
ota
l
Su s
p
e nd
ed So
l
i d
s(
T
S S
)
,a s
w
el l
a s si g
n
i f
i c an t
am
o un
t
s of p
ol lu
t
an t
s at t
a ch
ed
t
o s u sp
en
d
ed
s ol i d
s,w i l
l
b
e r em
o v ed
(
N C D E N R
1
9 9 9
)
.P
o nd 2 h
a s ap
e rm
i
t t
ed
n o rm
al
(
d
ry
-
w
e at
h
e r)
s u rf
a
c e a r e a of
1 2
,86
0
s
q
u a r ef
e et
(
1 1
9
0
sq
u a r em
et
e r s)
w h i
ch m
ay
d
o ub l
ed
u ri
ng
st
o rm
e v e nt
s a nd
a n o rm
al
v o
lu
m
e of
4
6
,0 0 0
c ub i
cf
e et
(
1
,3 0
3
,0 0
0
L
)
t
h
at
c an
in c r e a s e
t
h
r e ef
ol d d
u ri
ng
st
o rm
s(
C i
t
y
o
f
D
u rh
am S
t
o rm w
at
e rSe r v
i
c e s2 0 0 5
)
.T h
edr
a
in a
g
e a r e af
o rp
o nd
2
i
s14
.
6
a c r e s ,w i
t
h
a
p
p
r o xi m
at
el
y
h
al f
of
t
h
at
a r e ai m
p
e r vi
o u s s u rf
a c e.P
o nd 1 d
o e s n ot
h
a v el is
t
ed
s u rf
a c em
et
e r s)
, an
d
a s s um
i
n
g t
h
e s am
e a v e r ag
ed
ep
t
h
a sp
o nd
2
, a v ol
um
e of 5
,4
0 0
c ub i
cf
e et
(
1
5 3
,0
0
0 L
)
P
o nd
1
i
s n e a rl y
r o u nd
,w h i l
ep
o nd 2 h
a s al
e ng
t
h
t
ow i dt
h
r at
i
o of
a
p p
r o xi m
at
el y 2
:1
P
h
a s eI
(
si
ng l
eg
r ab
s am
p
l
e s am p l i
ng
)
of
t
h i
s stu
d
y
i
n
v ol
v ed
g
r ab
s am
p
l
e sc o
l l
e ct
ed
u nd
e r st
o rm
an
d d
ry
w
e at
h
e r(
b
a ck
g
r o u nd
)
c o nd it
i
o n sd
u ri
ng t
h
ep
e ri
od
of J
u n et
oN
o v em b
e r2 0
0 6
A l
l
s am
p
l
e sw
e r e c ol l
e ct
ed i
n st
e ri l
e4
-L
p l
a st
i
cb
ot t
l
e s o r c ub i
t
ai
n e r sa n
d
tr a n s
p
o rt
ed
on
i
c et
ot h
el
ab
o r at
o ry
.B
a ck
g
r o u nd
c o nd i
t
i
o n sw
e r ed
efi
n ed
a s at
l
e a st
th
r e ed
ay
sw
it
h
o ut
ap p
r e ci
ab l
ep
r e ci
p
i
t
ati
o n(
i
e.,
p
r e ci
p
it
ati
o nth
at
c a u s ed
a ch
an
g
ei
nth
es
t
r e am f l
ow h
y
d
r og
r ap
h
)
.A
st
o rm
e v e nt
w
a sd
efi
n ed
a s r ai
nf
al l
t
h
at
i
n c r e a s ed
st
r e am
fl
ow
at
l
e a st
f
o u rf
ol
d
o v e rp
r e-s
t
o rm
l
e v el
s.A
t
ot
al
of 8
si
t
e sw
e r e s am
p
l
ed f
o r e a ch
s
t
o rm
e v e nt
,i
n cl
ud i
n
g
st
r e et
r u n off
,p
o nd i
nfl
ow
, an
d
p
on
d
o ut
fl
ow
at p
o nd
s1
a nd
2
, a sw
el l
a s st
r e am
si
t
e s1
a nd
2
S
t
r e et
r un
of f w
a s ob
t
ai
n ed
a s r u n of f
e nt
e r ed
t
h
e sto r
m
s ew
e rd
r ai
n st h
at
w
e r e cl
o s e st t
o e a ch
p
o nd
.T h
e r u n of f
a nd
p
o nd
si
t
e sw
e r e s am
p
l
ed
s e v e r al
h
o u r s af t
e r r ai
n c om m
e n c ed
, a nd
th
e st
r e am
si
t
e sw
e r e s am
p
l
ed
a s cl
o s et
oth
ep
e ak
of
th
es
t
o rm h
y
d
r og
r ap
h
a sp
o s si b l
e.B
a ck g
r o u nd
s am p l
e si
n cl
ud
ed p
o nd i
nfl
ow
an
d
o ut
fl
ow
(
t
h
e r ew
a s n o r u n of f
)
, a nd
t
h
et
w
oi
n
-s
t
r e am
si
t
e s.S
am
p l
e sf
r om
s e v en
st
o rm
e v e nt
s a nd
f
i v eb
a ck
g
r o un
d p
e ri
od
sw
e r e c ol l
e ct
ed
a nd
an
al
y
z ed d
u ri
ng
p
h
a s eI
, alt
h
o ug
h
t
h
r e e of
th
e st
o rm
ev e n
t
sd i d
n ot
i
n cl
ud
e r u n of f
a s s am
p l
e sw
e r et
ak
e nt
o ol
o ng
aft
e r r ai
nf
al l
c e a s e
d
.P
h
a s eI I
(
i
nt
r a st
o rm
s am
p
l i
n
g
)
w
a s c o nd
u ct
ed J
u n e3
-4
,
2
0 0 7
a nd i
n
v ol
v ed
m
o ni
t
o ri
ng t
h
ei
nfl
ow
a nd
o ut
fl
ow
of
p
o nd
2
o v e rt
h
e c o u r s e of
a ni
nd i
vi d
u al
st
o rm i
n an
e
ff
o rt t
ofi
nd fl
ow
-w
ei gh
t
ed m
e a n c o nc e
nt
r at
i
o
n s of m i
c ro
b i
al i
nd i
c at
o r s a nd p
a rt
i
cl
e sa n
d
e st
i m
at
et
h
ep
o nd
'u s
i
ng
ap
o rt
ab l
ef l
ow
m
et
e r(M
a r a sh
-M
c
B i
m
ey
F
l
o-M
at
em
od
el 2 0 0 0
)
T h
eh y d
ra ul i
cr e s
i d
e n c et
i m
ef
o rt
h i
s st
o rm w
a s e st
i m
at
ed
t
ob
e a r o u nd
t
h
r e e a nd
ah
al f h
o u r s(
s e eA
p p
e nd i
xC f
o rd
et
ai l
s)
.A f t
e rt
h
e c om
p
l
et
i
o n of
p
h
a s eI
,i
t
w
a sd i
s c o v e r ed
t
h
at
t
h
e r e a r e a ct
u al
l
y
t
h
r e ei
nl
et
si
np
o nd
1
.h
il
ow fl
ow
c o nd i
t
i
on
s(
i
.e.b
a ck g
r o u nd
s am p l i
n
g
)
t
h
e r ei
s o nl
y
fl
ow i
nt
h
e s am p l
ed i
nl
et
,b
ut
u nd
e r st
o rm
c o nd i
t
i
o n s ab
o ut 2
0 %
of
t
h
e
fl
ow
c om
e st
h
r o ug h
t
w
os
m
al l
e ri
nl
et
sI
nfl
ow w
at
e r at
t
h
e s am p l i
ng p
oi
nt w
a s c om
p
a r ed
t
o s am p l
e sg
r ab b
ed
at
al
o c at
i
o nw
h
e r et h
ew
at
e rfr
om
al l
t
h
r e ei
n
l
et
sw
a sm
i
x ed
, an
d i
t
w
a sf
ou
nd
t
h
at t
h
ec o
m
p
o si
t
i
o n of
t h
ew
at
e rd i d
n ot
di f f
e rw
i
t
h
r e sp
e ct t
of
e c al
c ol i f
o rm
,E
. c ol i
, an
d T
ot
al
O
rg
a ni
cC
a rb
o n(
T O C
)
.T h
e r ew
e r e s om
ed
i f f
e r e n c e sf
o r e nt
e r o c o c ci
,
p
a rt
i
cl
ec o n c e n
t
r at
i
o n, a nd
T
S S
,b
ut
t
h
ey
w
e r e n ot
c o n si
st
e nt
i
nd i
r e ct
i
o n o rm
ag
ni
t
ud
e.T
h
ed
at
ar e
p
o rt
ed h
e r e r ep
r es
e nt
st
h
ei
n
fl
ow fr
om
t
h
e si
ng l
ep i p
e,w h i
ch
ap p
e a r st
ob
e a r e a s o n ab l
ee s
t
i
m
at
e of
t
h
e o v e r al l i
nfl
ow
.L
ab
o r at
o ry
A
n al
y
si
sT
h
ep
a rt
i
t
i
o ni
ng p
r o c ed
u r e u s ed i
nt h
i
sw
o rk h
a sb
e e nd
e s c ri b
ed i
nd
et
ai l i
nt
h
el i
t
e r at
u r e(
C h
a r a ck l i
s et
al
.2 0
0 5
;
F
ri
e s et
al
.2 0 0
6
;
K
r om
et
i
s et
a
l
.2 0
0 7
)
,
b
ut
s om
eb
ri
ef d i
s c u s si
on
i
s of f
e r ed h
e r e.A f
t
e r r et
u r ni
ng t
ot
h
el
ab
o r at
o ry
,s a
m
p
l i
ng
c o nt
ai
n e r sw
e r eg
e nt
l
y
i
n v e rt
ed
s e v e r al
t
i m
e si
n o rd
e rt
o r e s u sp
e nd
a ny
m
at
e ri
al
t
h
at
m
i
g
h
t
h
a v e s et t
l
ed d
u ri
n
g t
r an
sp
o rt
.T
h
e s am
p l
ew
a st
h
e nd i
vi d
ed i
n t
ot
w
op
a rt
s;
o n el i
t
e rw
a s c e nt
ri f
ug
ed
a nd
t
h
e ot
h
e rl i
t
e rw
a s n ot
(
F i
g
u r e3
)
.A S
o r v al l R C
-